Charging is completely separate from the LED driver. Anduril’s code is irrelevant to this topic.
You participated in the recent poll about built-in charging, so I assume you’re aware of people’s reasons for not wanting it, but there are a bunch of other reasons on top of all the stuff people mentioned in that thread… like engineering, cost, and safety.
Charging a single-cell LiIon-only light isn’t so bad, though it’s still typically not great. NiMH is much more difficult though, and in a light which can take alkaline primaries, lithium primaries, NiMH, NiCD, LiIon, and LiFePO4… even if all the circuitry could fit inside such a small light, the SP10 is primarily sold to non-enthusiasts who may not even know not to charge an alkaline cell. I handled Sofirn’s Amazon returns for a while, and you know what the #1 reason was for returns? Customers couldn’t figure out that they needed to remove the shipping protection stickers from batteries.
This light needs to be safe for that market.